Protein evolution revisited

ABSTRACT

Antifreeze proteins (AFPs) protect marine fishes from freezing in icy seawater. They evolved relatively recently, most likely in response to the formation of sea ice and Cenozoic glaciations that occurred less than 50 million years ago, following a greenhouse Earth event. Based on their diversity, AFPs have independently evolved on many occasions to serve the same function, with some remarkable examples of convergent evolution at the structural level, and even instances of lateral gene transfer. For some AFPs, the progenitor gene is recognizable. The intense selection pressure exerted by icy seawater, which can rapidly kill unprotected fish, has led to massive AFP gene amplification, as well as some partial gene duplications that have increased the size and activity of the antifreeze. The many protein evolutionary processes described in Gordon H. Dixon’s Essays in Biochemistry article will be illustrated here by examples from studies on AFPs.

Abbreviations: AFGP: antifreeze glycoproteins; AFP: antifreeze proteins; GHD: Gordon H. Dixon; SAS: sialic acid synthase; TH: thermal hysteresis

KEYWORDS:

• Antifreeze proteins
• protein evolution
• structural biology
• X-ray crystallography
• gene amplification

Acknowledgments

Research performed in house was supported by Canadian Institutes of Health Research and the Protein Engineering Network of Centres of Excellence. PLD holds the Canada Research Chair in Protein Engineering.

Disclosure statement

The authors have no conflicts of interest in regard to the publication of this review.

Additional information

Funding

This work was supported by the Canada Research Chairs, Canadian Institutes of Health Research, and Protein Engineering Network of Centres of Excellence.

Notes on contributors

Peter L. Davies

Planning, writing, and editing the review based on a common interest and research experience in the subject area: PLD and LAG.